Central Control Entity Research Articles

IMPACT OF BLACK HOLE ATTACK ON THE PERFORMANCE OF DYNAMIC SOURCE ROUTING AND OPTIMIZED LINK STATE ROUTING PROTOCOLS IN MANETS

Mobile Ad-Hoc Networks (MANETs) are a collection of mobile nodes which are free to move from one place to another place without a central control entity. In MANETs the nodes are dependent on each other and the communication among mobile nodes is multi-hop due to which there are security issues in the MANETs protocols. Optimized Link State Routing (OLSR) and Dynamic Source Routing (DSR) protocols are mostly used as proactive and reactive routing protocols in MANETs. This research work analyzed the performance of the OLSR and DSR protocols in the presence and absence of black hole (BH) attack in terms of throughput, end-to-end delay, packet delivery ratio (PDR), and network load in various scenarios using OPNET Modeler 14.5 simulator. The results obtained in this research show that BH attack significantly degrades the performance of both DSR and OLSR protocols but due to the reactive nature of DSR routing protocol the performance is more degraded in DSR routing protocol as compared to OLSR routing protocol in the presence of BH attack.

Empirical agent-based model simulation for the port nautical services: A case study for the Port of Rotterdam

Large deep-sea ports are complex environments where different parties work together to handle ships. The ability to model the deep-sea ship handling process is desired with the goal of what-if ex-ante scenario assessment. In this paper, an agent-based model for simulating the port nautical services in the Port of Rotterdam is presented. The model is constructed based on the real-world process descriptions, and is calibrated and validated based on empirical data. We further show that the model can be used as a tool to analyse scenarios, of which two cases are presented in this paper. The bottom-up modelling approach used in this study provides a methodology to grasp the complex, multi-organizational, aspects of the port nautical service chain. The developed model can be seen as a prototype for a decision support tool for the Port of Rotterdam's Port Authority to analyse the impact of measures on this multi stakeholder system without a central control entity. The modelling approach is scalable to other complex large deep-sea ports with necessary adjustments, in terms of spatial elements, agent representations and empirical data.

Building a Community of Users for Open Market Energy

Energy markets are based on energy transactions with a central control entity, where the players are companies. In this research work, we propose an IoT (Internet of Things) system for the accounting of energy flows, as well as a blockchain approach to overcome the need for a central control entity. This allows for the creation of local energy markets to handle distributed energy transactions without needing central control. In parallel, the system aggregates users into communities with target goals and creates new markets for players. These two approaches (blockchain and IoT) are brought together using a gamification approach, allowing for the creation and maintenance of a community for electricity market participation based on pre-defined goals. This community approach increases the number of market players and creates the possibility of traditional end users earning money through small coordinated efforts. We apply this approach to the aggregation of batteries from electrical vehicles so that they become a player in the spinning reserve market. It is also possible to apply this approach to local demand flexibility, associated with the demand response (DR) concept. DR is aggregated to allow greater flexibility in the regulation market based on an OpenADR approach that allows the turning on and off of predefined equipment to handle local microgeneration.

Energy Management System for an Energy District With Demand Response Availability

During recent years the electricity supply chain (electricity production, consumption, distribution, storage, and load management) has changed. In this context a new term appears: the prosumer, that is both a consumer and producer of energy in the same entity. In the paper, an energy management approach of several prosumers aggregated in a coalition, the energy district (ED), and coordinated through a central control entity, the coalition coordinator, is proposed. The aim of the coalition coordinator is to maximize the coalition utility also reducing in this way the reverse energy flows at the point of delivery by an appropriate demand response program. The application on an Italian residential housing area is illustrated. The numerical results demonstrate the effectiveness and attractiveness of the proposed energy management scheme.

Distributed spectrum sharing scheme for multiuser orthogonal frequency-division multiplexing cognitive radio networks

This paper presents a novel spectrum sharing design aiming at optimising the performance of a Multiuser Orthogonal Frequency-Division Multiplexing (MU-OFDM) Cognitive Radio Network (CRN) that consists of multiple secondary Transmitter-Receiver (Tx-Rx) pairs. For most MU-OFDM systems, the Exclusive Subchannel Assignment (ESA) is an efficient resource allocation method. Nonetheless, it is inappropriate for the network considered in this paper, because subchannels sharing among secondary Tx-Rx pairs can further improve the system performance. We investigate the Weighted Sum Rate (WSR) maximization problem under the Shared Subchannel Assignment (SSA), where each subchannel is shared by multiple secondary Tx-Rx pairs. With Lagrangian duality technique, we decompose the original resource allocation problem into several sub-problems on each subchannel and propose a duality-based subchannel sharing approach. For practical realisation in the cognitive systems without central control entity, a distributed duality-based WSR maximization scheme is presented. Simulation results manifest that the proposed scheme achieves significantly better performance than ESA duality scheme.

Design of a Multiagent‐Based Voltage Control System in Peer‐to‐Peer Networks for Smart Grids

AbstractEnergy management in distribution grids is one of the key challenges that needs to be overcome to increase the share of fluctuating renewable energies. Current control systems for energy management mainly demonstrate centralized‐ or decentralized‐hierarchical control structures. Very few systems manifest a fully decentralized multiagent‐based control structure. Multiagent‐based control systems promise to be an advantageous approach for the future distributed energy supply system because no central control entity is necessary, which eases parameterization in case of grid topology changes, and the agents are more stable against failures and changes of control topologies. Research is necessary to prove these benefits. In this study, we introduce a design of a multiagent‐based voltage control system for low‐voltage grids. In detail we introduce cooperative decision‐making processes and software solutions that allow the agents to perceive and control their environment, the agent‐discovery and localization in different types of communication networks, agent‐to‐agent communication, and the integration of the multiagent system in existing grid‐control infrastructures. Furthermore, the study proposes how different existing technologies can be combined into an applicable multiagent‐based voltage control system: the Java/OSGi‐based OpenMUC framework allows a generic field–device interaction; peer‐to‐peer discovery and session establishment functionalities are combined with the agent communication defined by the Foundation for Intelligent Physical Agents (FIPA). The ripple control‐signal technology is applied as a fallback communication between the agent and a central grid‐control center.

A Simple Decentralized Charging Control Scheme of Plug-in Electric Vehicles for Alleviating Wind Farm Intermittency

Variable power output from large-scale wind farms present new challenge of balancing power system load with generation. To alleviate this problem, this paper proposes a decentralized charging control scheme for plug-in electric vehicles (PEVs) to neutralize wind power fluctuations. In the proposed scheme, each PEV autonomously adjusts its power in response to a real-time directing signal and based on its own urgency level of charging. No intelligent central control entity is needed. Simulation results demonstrate the effectiveness of the proposed charging control in directing PEV power to counteract wind power fluctuations. Also, proportionally fair distribution of counteracting duties among PEVs can be achieved so as to meet heterogeneous charging requirements of PEV users, and the total utility of the PEV fleet is proven to be maximized.

A decentralized charging control strategy for plug-in electric vehicles to mitigate wind farm intermittency and enhance frequency regulation

This paper proposes a decentralized charging control strategy for a large population of plug-in electric vehicles (PEVs) to neutralize wind power fluctuations so as to improve the regulation of system frequency. Without relying on a central control entity, each PEV autonomously adjusts its charging or discharging power in response to a communal virtual price signal and based on its own urgency level of charging. Simulation results show that under the proposed charging control, the aggregate PEV power can effectively neutralize wind power fluctuations in real-time while differential allocation of neutralization duties among the PEVs can be realized to meet the PEV users' charging requirements. Also, harmful wind-induced cyclic operations in thermal units can be mitigated. As shown in economic analysis, the proposed strategy can create cost saving opportunities for both PEV users and utility.

Active Coordination of Thermal Household Appliances for Load Management Purposes

In this paper, a coordination approach for thermostat-controlled household appliances is developed. Under consideration are heating and cooling devices such as refrigerators, freezers, water boilers and heat pumps, which are usually characterized by an intermittent (duty cycle) operation. Without influence from the outside, an internal hysteresis switching controller toggles the “on/off” state of a device when its temperature boundary is reached. In order to realize the approach proposed here, the devices are connected to a central control entity by two-way communication. The coordination consists of a step-wise heuristic solution of a binary optimization problem, which serves to select a number of devices in each time step that are subject to compulsory switching, i.e. toggling the “on/off” state. It allows a large group of devices to track a setpoint trajectory with its aggregated power consumption, acting like a distributed virtual energy storage, while the individual temperature bounds of the appliances are not violated. This behavior can be used for grid-control purposes, such as the provision of active power reserves. It will be shown that the group of appliances can be characterized by an approximate aggregated dynamical model consisting of a first-order differential equation together with an approximate aggregated nonlinear cost function penalizing the control actions. The developed methodology is evaluated in a numerical simulation with a small appliance cluster corresponding to a residential housing area.

Virtual Power Plant as A Remedy to The Power Crisis Of Bangladesh: A Case Study-CUET

A virtual power plant is a cluster of distributed generation installations (such as microchip, wind-turbines, small hydro, back-up genets etc.) which are collectively run by a central control entity. The concerted operational mode shall result in an extra benefit as to deliver peak load electricity or load following power at short notice. Bangladesh is facing acute power crisis like other developing countries. As we have limited resources we have to think economically. VPP is playing good role in European & American market. So we have taken VPP as a solution for power crisis. In this thesis, we have taken CUET as a reference model. To solve the power crisis in CUET & to supply power to the main grid a small virtual power plant is designed .Whole CUET is divided into three regions for designing purpose. By using MATLAB simulink environment machine characteristic curves are derived & cost is calculated. KEY WORDS: VPP; MATLAB; DG; CUET; MCCB; DER; LDC. DOI: http://dx.doi.org/10.3329/mist.v3i0.8054